I have a 2003 Tahoe LT with rear heat that won't get hot. The A/C works fine and it blows plenty of air, but when I turn the temp control to heat, nothing changes. I was told this could be as simple as a resistor or switch in the panel. I was wondering if anyone had experienced similar problems and what the cause was. Thank you.

Brian:

I came here with the EXACT same problem - rear air blows but doesn't get hot. On a 2004 Tahoe. Looking thru the fuse info.....

Red

I have the same problem. The fix is in the rear looking in from the rear of the vehical if you pull of the rear panel on the right side there is an air unit along with a control box and two motors. The motor closest to the front, controls switching from floor to ceiling. The rear motor switches from heat to cool. So your rear motor that controls that is probably bad. If you replace that motor it should fix your problem. Hope this helped.

Thanks Hootjm. I pulled the panels and just as you described, the rear stepper motor is not working. I'll try to get one at the local parts store.

update - I changed out the "air door actuator" and thought I had it fixed since I was getting heat. But today its a balmy 70 degrees so I tried the AC. nope - now its stuck on heat. neither the front nor rear controls will cause it to switch to cool/cold air. There must be a temperature sensor bad somewhere - anyone have any details? thanks

-Redonthehead... did you get it resolved?

I have the exact problem with identical symptoms... I changed out the "temperature actuator" for the rear and it still didn't correct the problem. :banghead:

Any one else have any ideas?

Thanks in advance!

I also have an '03 Tahoe in which I am having rear heat problems. I took it to a small shop in town and was told that the "blend air actuator" was fried; they replaced it and it worked for a day and then went back to blowing only cold air. I took it back to them and was told that there are gears on the actuator that need synchronized and that they are very sensitive; they re-synchronized the gears and also found that the ground to the actuator had higher than normal resistance that probably caused the first actuator to go bad. They replaced the connection on the ground and re-synchronized the gears. Now, however, the actuator is switching back and forth between heat and A/C. I talked with them and will be taking it back in on 2/15. I will post any more info that I get from them. I hope this helps.

Sounds like this re-sychronization of gears is crucial. Can you "ask" what they did to sychronize the gears? I searched a bit, but wasn't able to locate any process to do this.

Guess I'll need to check the ground connection as well.

Look forward to hearing back after your visit. Thanks for the update!

I also have an '03 Tahoe in which I am having rear heat problems. I took it to a small shop in town and was told that the "blend air actuator" was fried; they replaced it and it worked for a day and then went back to blowing only cold air. I took it back to them and was told that there are gears on the actuator that need synchronized and that they are very sensitive; they re-synchronized the gears and also found that the ground to the actuator had higher than normal resistance that probably caused the first actuator to go bad. They replaced the connection on the ground and re-synchronized the gears. Now, however, the actuator is switching back and forth between heat and A/C. I talked with them and will be taking it back in on 2/15. I will post any more info that I get from them. I hope this helps.

I have a 2003 Yukon with the same problem. Did you get this resolved yet? What was the result?